1986 Stalls Out In Reverse

[Joseph A.]

I have a 1986 Corvette with an automatic transmission, (700R4). The engine stalls when the transmission is put into reverse after the engine is warmed up. But, if the engine is cold, after setting overnight it does not stall. Has anybody experienced this problem. The engine and transmission have been rebuilt and only have a 1,000 miles. This problem never happened before the rebuild of the transmission. Any help would be appreciated.

Thanks Joey

[Wayne W.]

Re: 1986 Stalls Out In Reverse

Check the signal from the back up switch to make sure it is signaling the computer to bump the RPMs up. It should signal in both Forward and Reverse though.

[Joseph A.]

Re: 1986 Stalls Out In Reverse

Wayne when you but the car in drive the RPMS Bump up. But the cr just stalls out when you shift into reverse.

[Wayne W.]

Re: 1986 Stalls Out In Reverse

Check the adjustment on the park neutral switch. It should tell the computer that it is in gear.

[Joseph A.]

Re: 1986 Stalls Out In Reverse

I have checked that. When you hook up the scan tool you get the proper readings. Also the IAC, TPS, idle, and minimum air rate have all been set to factory specs.

[Wayne W.]

Re: 1986 Stalls Out In Reverse

Sounds like you have done all of the normal checks.

[Joseph A.]

Re: 1986 Stalls Out In Reverse

What about the tcc engaging when the car is in reverse?

[Wayne W.]

Re: 1986 Stalls Out In Reverse

I guess that is possible, but not likely. If the TCC locks at idle it would be like letting out on a clutch with the wheels locked.

[Joseph A.]

Re: 1986 Stalls Out In Reverse

At idle the car idle's normal. But when you put the car in reverse it stalls. It only stalls when the motor is in closed loop and warmed up. TCC should only engage in gears overdrive, third gear, and second gear. It should not engage in reverse or first gear. When I put my car in first gear with the motor hot and in closed loop th engine goes down to 400 RPM's from six hundred RPM's but the computer picks the idle back up to around 600 RPM's. What I don't understand is why the computer will adjust the idle in first gear thur overdrive, But go into reverse with the engine hot and it stalls out. The only way you can not make the motor stall out is to hold the brake, put the car into reverse and give it gas and help the engine along. Once the RPM's get up the car idle's erractic but does not stall. You can feel the torque converter is locking up because you can feel it engaging. I did a little test today. When the car is in reverse and you help the engine along and bring the idle up and let the car roll back without pressing the gas it feels like TCC is engaging. If I had to guess where the problem is, I think its in the valve body or the reverse circuit. Any help would be greatly appreciated.

Joey

[Wayne W.]

Re: 1986 Stalls Out In Reverse

Unplug the wires from the transmission to the computer and see if that makes any difference. If it does not, It would seem to be mechanical, and I would take it back to the transmission man.

[Joseph A.]

Re: 1986 Stalls Out In Reverse

Wayne, thanks for all the help. You guys here are awesome.

Joey